The AWIPEV arctic station is situated at 79 degrees latitude. This is even 8.4 degrees closer to the pole than the Neumayer station in Antarctica. Concerning climate this place is much more hospital but polar day and polar night last longer. Ny-Ålesund lies in the North of the Zeppelin mountain which shadows the sun in spring and fall. Because of this the sun cannot be seen from the platform of the Observatory during winter for more than 5 months. Soon that will be the case again.
Polar Day und Night
The closer one gets to the pole, the less curved the sun path on the sky will be. At Ny-Ålesund the difference between upper and lower culmination (at noon and midnight) is only 22 degrees. Living in the mid latitudes people are used to a difference that is much higher than the change of 47 degrees from winter solstice to summer solstice. If it is lower because the place is situated within the polar circle, the sun will not rise or set for several days. I always had my windows taped with aluminium foil for being able to sleep during the polar day.
How bright it gets at noon during the polar night depends on how deep below the horizon the sun will be. At midwinter the sun will always stay more than 12 degrees below. This is beyond the nautical twilight and there is only very little scattered light on the sky. Close to the luminous village this cannot be recognized. But already mid of January there is a faint bluish glimmer on the sky at noon, indicating that December has ended and that the daylight is coming back slowly.
Viewed from the earth, new moon is always close to the sun. If our sun would not be that bright, it could therefore be seen together with the sun on the polar day but never during polar night. At full moon, earths satellite is located opposite the sun. As a consequence if the sun is shining, the full moon will always be below the horizon. Luckily the full moon is standing on the night sky 24h during the polar night when the sun is down. Then it does not set for several days. If the weather is good, the moon turns night into day and makes hikes possible even during the dark season.
Instruments like the FTIR of the university Bremen need direct sunlight. This device takes spectra of the sun to calculate the concentration of trace gases in the atmosphere. To get data even during the polar night, scientists developed the device further to measure also moon light. A part of this moon light measurements during the full moon phase are one of the tasks of the station engineer.
The Starry Sky
From the equator the stars from both, northen and southern hemisphere can be seen. In the arctic however only the northern sky is visible. Even the well known constellation Orion, which can be spoted easily in the mid latitudes in winter, never rises completely above the mountains. On the other hand most of the stars stay circumpolar: They never set.
There is a mirror telescope in the dome of the observatory. It is not useable for visual observations. Connected to it is a sensitive star spectrometer. It is used to measure the brightness of the circumpolar star Vega. The results are compared with the expected luminosity of the star. As a result the wavelength dependent absorption of the atmosphere comes out. Once more standard instruments as the sun spectrometer do not work in the polar night and special equipment is needed to get comparable data during dark season.
Get the Night Sky of Ny-Ålesund on your Computer!
Stellarium is a free software that can visualize the night sky as well as the orbit of sun, moon and planets on your home computer. It can show you the starry sky from all places on earth (even outer space) and runs on most computer systems. It is even more fun if you have the right landscape for it: Download the landscape of Ny-Ålesund and soon you will find yourself at 79 degrees North!
…and that is how it works:
- Download the software Stellarium: http://www.stellarium.org
- Install the software into the suggested folder
- Download the panorama of Ny-Ålesund: http://pano.imageo.ch/stellarium/nyalesund_lidar.zip (50 Mb)
- Unpack the zip file and copy the folder into the \landscapes directory of the program. On Microsoft windows this directory can be found on C:\Programme\Stellarium\landscapes
- Run the software
- Press F4, then “Landscape”: Choose the Ny-Ålesund panorama from the list. In the Options field check all boxes, especially the first, third and the two last ones.
- Most likely Stellarium will not automatically load the coordinates for Ny-Ålesund. That is why you should press F6 to show the current location. If the latitude is not N78°55’23”, please change it, add the new coordinates to the list and mark it as default: Latitude: N78°55’23.01″; Longitude: E11°55’21.00″; Altitude: 20m; Name/City: Ny-Alesund; Country: Norway; Planet: Earth
- When Stellarium is started, it will show you the night sky at the current time. If you want to change date or time press F5 and do so.
- You can also find all these functions as buttons on the left side of your screen. The most important features in the command list on the bottom of your screen are the buttons for changing the speed on the right. With F1 you can get some help if needed.
- Do you also want to have a landscape for your home or holiday destination? Check this out: http://www.stellarium.org/wiki/index.php/Landscapes
- Is your computer fairly old and has difficulties with the high resolution panorama of Ny-Ålesund? Get a smaller version and try again: http://pano.imageo.ch/stellarium/nyalesund_4k.zip (13 Mb).
- The panorama is labeled in green with a big font size. If you do not like this, the labels can be turned off where you have loaded the panorama. People who feel confident can also change the configuration file config.ini. Change the following two lines underneath the line [landscape]: label_color = 0.1,0.2,0.3; label_font_size = 12
There exist two config.ini files. In Windows the dominant file is located in the folder C:\users\…\AppData\Raming\Stellarium\
Now let’s see if you can find out yourself when the sun will rise and set at the AWIPEV observatory:
- Sun will shine last time of the year: October 5th, 2016, 08:59
- Start of the polar night: October 22nd, 2016
- Midwinter, winter solstice: December 21st, 2016
- End of the polar night: February 20th, 2017
- Sun will shine first time of the year: March 8th, 2017, 08:15
- Start of the polar day: April 19th, 2017
- Sun will be visible 24h: April 29th, 2017
Let’s hope for some good weather that all people of Ny-Ålesund can inhale the last rays of sunshine.